Improvement in jig-saws



- -2 Sheets--Sheet2. a. s. WILLIAMS.

Hg-S'aw.

N ,1 1,5 3 Patented March 30,1875.

THK GRAPHIC C0.PHOTO -L|TN.39&41 PARK PLAGE,N-Y.

GILES S. WILLIAMS, OF MADISON, WISOONSIIT.

IMPRQVEMENT IN JlG-SAWS.

Specification forming part of Letters Patent No. 161,583, dated March30, 1875; application filed December 10, 1874.

To all whom it may concern:

Be it known that I, GILEs S. WILLIAMS, of Madison, in the county of Daneand State of Wisconsin, have invented certain new and usefulImprovements in Jig-Saws; and I do hereby declare the following to be afull and exact description of the same, reference being had to theaccompanying drawings, forming part of this specification, in whichFigure 1 is a side elevation, partly in section, showing myimprovements; and Fig. 2 is a front elevation of the same.

Similar letters of reference in the accompanying drawings denote thesame parts.

My invention has for its object to improve the construction of jig-sawsfor the general purpose of rendering them more complete and efficient intheir operation. To this end the invention consists, first, in vibratingthe saw-frame by means of a compound double toggle-lever, connecting itdirectly with the operating-treadle. It also consists in connecting thecompound double toggle-lever to the frame of the machine, by means of avibrating pivot-arm, for the purpose of in creasing the reciprocationsof the saw. It also consists in connecting the compound doubletogglelever with one or more balancewheels by means of a crank-shaft andconnecting-rod, for the purpose of equalizing the movements of the saw.

In the accompanying drawings, A is the frame of the machine, made of therequisite height, and provided at its rear end with the upright B, andat its front end with the sawing-table G. D is the saw-frame, composedof the beams E E, pivoted or hung between the uprights, and connected attheir rear ends by a strap or loop, F. G 1s the saw, passing through thetable 0 in the usual manner, and connected to the forward ends of thesaw-frame by the loops H I. The loop I fits over the end of the upperarm, so as to move up and down thereon, and is provided with acam-lever, J bearing upon the top of the arm, by the operation of whichthe saw is strained or loosened. Between the loop F at the rear end ofthe saw-frame and the top of the upper beam a metal or rubber spring, K,is interposed to assist in preserving the tension of the saw, and tocompensate for the wear of the locking-cam lever. L is an upright,pivoted in a foot-bar, M, at the front of the frame, and N is thetreadle, mounted upon the pivot of the upright. 0 is a short bar or rod,pivoted at its upper end to the lower beam of the saw-frame beneath thesaw and P is a longer intermediate bar, pivoted to the top of theupright and lower end of the bar 0, so as to connect the two, as shownin Fig. 1. Q is an arm, hinged at its inner end to a central cross-bar,R, of the frame, and pivoted at its outer end to the center of the barP.

The several bars, together with the upright, form a compound lever, bythe operation of which the saw-frame is vibrated, while the arm Q,holding the center of the bar P in position, causes it to oscillate upona central pivot, and therefore increases the vibrations of the saw whenthe treadle is operated.

The inner end of the pivot-arm Q is necessarily hinged to the centralcross-bar, because its outer end moves through a short are when thecompound lever is in operation. Otherwise the connections must eithergive way, or the lever become immovable.

S is a pivoted rod, connecting the upper end of the upright with thecrank of a crossshaft, T, arranged at the rear of the frame, andcarrying two balance-wheels, U U.

When the compound lever is in operation the oscillations of the uprightcommunicate motion to the balance-wheels through the medium of theconnecting-rod and crank-shaft, for the purpose of steading themovements of" the compound lever, and therefore equalizing the strokesof the saw. Instead of employing two, one large balance-wheel may beused, if preferred.

By my invention the mechanism for operating jig-saws is greatlysimplified and cheap- L ened, while the efficiency of the machine isincreased by doubling the vibrations of the saw withirra given time, andrendering such vibrations steady and uniform.

Instead of applying the compound lever to a saw-frame it may be appliedto various other devices where a vibrating or reciprocating motion isrequired without departing from the spirit of my invention, as will bereadily understood.

Having thus described my invention, What I claim as new isit 1. Thecompound double toggle-lever connectin g the saw-frame of a jig-sawdirectly with the operating treadle, substantially as described, for thepurpose specified.

2. The vibrating pivot-arm Q, connecting the compound lever to the frameof the machine, substantially as described, for the purpose specified.

3. The combination of the compound lever, vibrating pivot-arm Q, and thebalance-Wheels with the saw and frame of the machine, substaantially asdescribed, for the purpose specifie GILES S. WILLIAMS.

Witnesses OLIVER SWIFT, BENONI S. WILLIAMS.

